Panel saws are known in the prior art for supporting and cutting large pieces of material, such as sheets of plywood, for example. Conventional panel saws comprise a frame that typically rests on a floor surface, and presents a front face that usually is slightly inclined from vertical, i.e., leans back away from the operator. Roller supports near the bottom of the front of the frame are spaced along the length of the frame for supporting the workpiece, such as a 4×8 sheet of plywood, for example, so that the workpiece leans back against the face of the frame and can be moved longitudinally on the frame. A circular saw, router, or other tool is mounted on the frame generally centrally of its length for up and down movement relative to the frame and thus relative to a workpiece supported on the frame for cutting, routing, or performing another cutting operation on the workpiece.
In use, a sheet of material to be cut, routed or otherwise treated is placed on the frame with the bottom edge of the workpiece resting on the rollers. If a vertical cut is to be made in the workpiece, the saw or other tool is moved along its support slides to an elevated position above the top edge of the workpiece. The workpiece is then moved longitudinally on the frame to a predetermined position for cutting a desired length or width of the workpiece from the sheet, and the tool is then turned on and moved downwardly on its slide supports to engage and cut the workpiece. Many conventional panel saws also enable the cutting tool to be positioned and held in a desired location spaced from the top or bottom of the frame, and oriented so that a horizontal cut or the like can be made in the workpiece as the workpiece is moved longitudinally past the tool.
The use of a panel saw frame to hold and support the work, and to hold and guide the tool, enables large workpieces to be more easily cut, and accurate and repetitive cuts or other operations can be relatively easily made. To enhance these functions, conventional panel saws can be provided with measuring tapes or devices that are mounted to the panel saw frame in a position to provide an indication of the position of the workpiece, and adjustable stops can be provided for engaging an edge of the workpiece to locate and hold the workpiece in a particular position while a cut or other operation is being performed on it. Spring rise limiters also are sometimes mounted on the frame to press rearwardly against the face of thinner workpieces to hold them against the frame and prevent undesired movement or “chatter” of the workpiece as an operation is being performed on it.
While conventional panel saws greatly facilitate the ease and convenience of cutting or performing other operations on large workpieces, such as 4×8 sheets of plywood, for example, they lack sturdiness and versatility in some of the attachments, such as edge stops, hold downs, rise limiters, and the like, that are provided for attachment to the panel saw to enhance its functionality.
Applicant's prior copending application Ser. No. 11/231,504 describes several improvements to conventional panel saws that minimize or eliminate the disadvantages of conventional panel saws as described above. Applicant's modified panel saw has improved attachments that engage the top edge, bottom edge, trailing edge, back surface and front surface of a workpiece, forming a pocket that limits movement of the workpiece along three mutually perpendicular axes. The improved attachments include a stand-off panel that can be mounted on the face of a panel saw frame to position the workpiece closer to the cutting tool, and interchangeable light duty and heavy duty edge stop assemblies. The light duty and heavy duty edge stops are respectively carried on separate edge stop guide assemblies that must be removed and replaced on the panel saw when it is desired to replace one type of edge stop with another. The edge stops in applicant's prior application are individually adjustable longitudinally relative to the workpiece, but they are all held in a fixed position in a direction perpendicular to the face of the workpiece and in order to place them in or remove them from operative service the entire edge stop assembly must be removed from the panel saw frame.
Accordingly, there is need for a panel saw that has performance-enhancing attachments that are sturdy and versatile in their use, and wherein heavy duty edge stops may be placed into and removed from service without requiring removal and replacement of the light duty edge stops or of the entire edge stop assembly. Further, there is need for an edge stop assembly that enables all the edge stops to be moved as a unit into and out of operative position.